<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
    <head>
        <title>CSS Test: Absolutely positioned non-replaced elements when both 'margin-left' and 'margin-right' are set to 'auto' and direction is right-to-left</title>
        <link rel="author" title="Microsoft" href="http://www.microsoft.com/">
        <link rel="help" href="http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width">
        <meta name="flags" content="ahem">
        <meta name="assert" content="When direction is 'rtl' and 'left', 'width' and 'right' are not 'auto', solve for 'margin-right' and 'margin-left' to equal values. If this would make 'margin-left' and 'margin-right' negative, then set 'margin-right' to zero and solve for 'margin-left'.">
        <style type="text/css">
            #div1
            {
                border: solid black;
                direction: rtl;
                height: 2in;
                position: relative;
                width: 2in;
            }
            div div
            {
                background: red;
                color: blue;
                font: 1in/1em Ahem;
                left: 1in;
                margin-left: auto;
                margin-right: auto;
                position: absolute;
                right: 1in;
                width: 1in;
            }
            /*
                left                    :   1in
              + margin-left             :   solve (auto)
              + border-left-width       :   0
              + padding-left            :   0
              + width                   :   1in
              + padding-right           :   0
              + border-right-width      :   0
              + margin-right            :   solve (auto)
              + right                   :   1in
              ====================================
              width of containing block :   2in

            So, margin-left and margin-right would be each -0.5in at this point. 

            "...unless this would make them (the two margins) negative in which case when direction of the containing block is 'ltr' ('rtl'), set 'margin-left' ('margin-right') to zero and solve for 'margin-right' ('margin-left')."

            So, under such extra constraint, 'margin-right' must become 0 and 'margin-left' must become -1in.
            */
        </style>
    </head>
    <body>
        <p>Test passes if the blue box fills the upper-left corner of the black box and there is no red visible on the page.</p>
        <div id="div1">
            <div>X</div>
        </div>
    </body>
</html>